The present invention relates to a film winding method, a method of loading a film in a lens-fitted film unit and a film supplying spool, and the invention is especially effective for winding a film whose leading edge is not perforated.
When winding a film on a film supplying spool in the case of a conventional film such as, for example, a 135 film, a film has been wound on a film supplying spool after causing claws provided on the film supplying spool and perforations on the film leading edge to engage with each other, because even a film leading edge has also been perforated. Further, there has been used another method wherein a leading edge of a film was folded to be inserted in a groove provided on a film supplying spool so that the film is wound.
However, in the method wherein a film is wound after claws provided on a film supplying spool and perforations on the leading edge of the film are caused to engage with each other as stated above has caused problems such as that the claws do not come off the perforations easily when removing the film from the film supplying spool and that the film wound in a cartridge is hard to be fed out of the cartridge due to deformation of the perforations when feeding out the film for developing.
In the case of a conventional film, it was able to be wound around a take-up spool despite the above-mentioned problems because the leading edge of the conventional film was perforated. However, the leading edge of a new film which has recently been disclosed in magazines or patent publications is not perforated, resulting in a problem that engagement between perforations and claws such as those in the past is impossible accordingly.
A cartridge wherein the new film is contained is shown in FIG. 1.
As shown in FIG. 1, cartridge C is composed of cartridge main body C1, take-up spool C2, film F taken up on the take-up spool C2, and light-shielding cover C4 that covers film gate C3. The light-shielding cover C4 is supported to rotate freely in the cartridge main body C1, and on one end of the light-shielding cover C4, there is formed key C5. Incidentally, in the present figure, the film gate C3 is not covered by the light-shielding cover C4 so that a film can be fed. On the other hand, when the film gate C3 requires to be shielded by the light-shielding cover C4 against light, key C5 is driven to rotate the light-shielding cover C4 counterclockwise by about 90.degree. so that the film gate C3 is shielded. Therefore, the film gate C3 needs, when it is taken out to a daylight room, to be shielded by the light-shielding cover C4 without fail, which is different from a conventional cartridge wherein a velvet is provided on a film gate.
As stated above, in a camera employing cartridge C, it is absolutely necessary that film F is totally rewound in cartridge main body C1 and film gate C3 is shielded by light-shielding cover C4 after completion of photographing, because the cartridge is taken out to a daylight room later. Further, this novel film continues to be contained in the cartridge as a negative film even after being processed to be returned to a photographer. On the occasion of reprinting, the negative film is thrusted out of the cartridge. Therefore, a film winding wherein a leading edge of a film is folded to be inserted in a groove provided on a film supplying spool can not be applied to this novel film. Namely, when a film leading edge is deformed when it is folded, the film can not be thrusted out of cartridge main body C1, which is a reason why the above-mentioned method can not be applied to the novel film.